2011-05-22 02:11:09 - Volcano Eruption - Iceland | |||||||||||||||||
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| Iceland's most active volcano erupted on Saturday, hurling a plume of ash and smoke far into the sky, which aviation officials were closely monitoring after another volcano shut European airspace for days last year . Authorities banned flights close to the Grimsvotn volcano but an official said the eruption was not expected to affect European airline traffic at least for the next 24 hours. The plume from the Grimsvotn volcano shot 20 km (12 miles) into the sky. The website of newspaper Morgunbladid said the eruption was more powerful than its last in 2004. "We have closed the area until we know better what effect the ash will have," said Hjordis Gudmundsdottir, spokeswoman for the Isavia civil aviation authority which has imposed a flight ban of 120 nautical miles around the area. Iceland's Eyjafjallajokull caused chaos when it erupted in April last year. Authorities halted flights due to fears that dust and ash would get into aircraft engines and cause accidents after the cloud was blown into European air traffic lanes. Grimsvotn lies under the Vatnajokull glacier in southeast Iceland, the largest glacier in Europe. When it last erupted in 2004 transatlantic flights had to be re-routed south of Iceland, but no airports were closed. Gudmundsdottir said the winds in the area were strong and that Isavia and the Icelandic meteorological office were coordinating with Volcanic Ash Advisory Centres (VAAC), which advise airlines about the movement of clouds of volcanic ash. There are two VAACs near Iceland, in London and the French city of Toulouse. "It can be a big eruption, but it is unlikely to be like last year," Icelandic Met Office geologist Hjorleifur Sveinbjornsson told Reuters, referring Eyjafjallajokull. He said the plume from Grimsvotn was going to the north and that the office's forecast for the next 24 hours was that ash would not affect European airline traffic. The volcano could erupt for several days, he added. One positive factor for air traffic was that the ash from this eruption was heavier, whereas the ash last year was lighter and so drifted further. Domestic airline Icelandair said no traffic had been affected. "We do not expect the Grimsvotn eruption to affect air traffic to and from the country in any way," said Icelandair communications director Gudjon Arngrimsson. Pictures on local media websites showed a thick cloud of white smoke like a mushroom cloud over surrounding mountains. "Grimsvotn is a very powerful volcano, so we're monitoring it closely, even if the last few eruptions have been harmless," University of Iceland geophysicist Pall Einarsson was quoted as saying on the website of Morgunbladid. "We do not expect this to be a big one as it's coming from the same crater as the last three eruptions, which were all small," he added. | |||||||||||||||||
| Posted:2011-05-22 02:11:09 [UTC] | |||||||||||||||||
Info4 Volcanic eruptions
World Map of Volcanoes, Earthquakes, Impact Craters, and Plate Tectonics | ||
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This site supports and extends a 1x1.5 m wall map available through the "Order" link [above]. |
 | | The map is designed to show Earth's most prominent features when viewed from a distance, and more detailed features upon closer inspection. The back of the map zooms in further, highlighting examples of fundamental processes, while providing text, timelines, references, and other resources to enhance understanding of this dynamic planet. The main and polar maps, above, are interactive, inviting you to make your own regional map, using whichever "layers" you choose. Data for any volcano, earthquake, or impact symbol can be found via the "Identify" tool. |
Back of Map | ||
Most new crust forms at ocean ridge crests, is carried slowly away by plate movement, and is ultimately recycled deep into the earth�causing earthquakes and volcanism along the boundaries between moving tectonic plates. Oceans are continually opening (e.g., Red Sea, Atlantic) or closing (e.g., Mediterranean). Because continental crust is thicker and less dense than thinner, younger oceanic crust, most does not sink deep enough to be recycled, and remains largely preserved on land. Consequently, most continental bedrock is far older than the oldest oceanic bedrock (see back of map). The earthquakes and volcanoes that mark plate boundaries are clearly shown on this map, as are craters made by impacts of extraterrestrial objects that punctuate Earth's history, some causing catastrophic ecological changes. Over geologic time, continuing plate movements, together with relentless erosion and redeposition of material, mask or obliterate traces of earlier plate-tectonic or impact processes, making the older chapters of Earth's 4,500-million-year history increasingly difficult to read. The recent activity shown on this map provides only a present-day snapshot of Earth's long history, helping to illustrate how its present surface came to be. Both the front and back of this map illustrate the enormous recent growth in our knowledge of planet Earth. Yet, much remains unknown, particularly about the processes operating below the ever-shifting plates and the detailed geological history during all but the most recent stage of Earth's development. | ||
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Volcano
A volcano is a mountain that opens downward to a reservoir of molten rock below the surface of the earth. Unlike most mountains, which are pushed up from below, volcanoes are built up by an accumulation of their own eruptive products. When pressure from gases within the molten rock becomes too great, an eruption occurs. Eruptions can be quiet or explosive. There may be lava flows, flattened landscapes, poisonous gases, and flying rock and ash.
Because of their intense heat, lava flows are great fire hazards. Lava flows destroy everything in their path, but most move slowly enough that people can move out of the way.
Fresh volcanic ash, made of pulverized rock, can be abrasive, acidic, gritty, gassy, and odorous. While not immediately dangerous to most adults, the acidic gas and ash can cause lung damage to small infants, to older adults, and to those suffering from severe respiratory illnesses. Volcanic ash also can damage machinery, including engines and electrical equipment. Ash accumulations mixed with water become heavy and can collapse roofs. Volcanic ash can affect people hundreds of miles away from the cone of a volcano.
Sideways directed volcanic explosions, known as "lateral blasts," can shoot large pieces of rock at very high speeds for several miles. These explosions can kill by impact, burial, or heat. They have been known to knock down entire forests.
Volcanic eruptions can be accompanied by other natural hazards, including earthquakes, mudflows and flash floods, rock falls and landslides, acid rain, fire, and (under special conditions) tsunamis.
Active volcanoes in the U.S. are found mainly in Hawaii, Alaska, and the Pacific Northwest. Active volcanoes of the Cascade Mountain Range in California, Oregon, and Washington have created problems recently. The danger area around a volcano covers approximately a 20-mile radius. Some danger may exist 100 miles or more from a volcano, leaving Montana and Wyoming at risk.
What is the history of volcanic eruptions where I live?
How can I protect myself from a volcanic eruption?
Find a Volcano by Region
Smithsonian Institution, Global Volcanism Program
| Mediterranean and W Asia | Africa and Red Sea | Middle East and Indian Ocean | New Zealand to Fiji | Melanesia and Australia | Indonesia | Philippines and SE Asia | Japan, Taiwan, Marianas | Kuril Islands | Kamchatka and Mainland Asia | Alaska | Canada and Western USA | Hawaii and Pacific Ocean | México and Central America | South America | West Indies | Iceland and Arctic Ocean | Atlantic Ocean | Antarctica |
All of the base maps in this section, for the world and volcanic regions, were generated using ER Mapper.
Citation Guidelines for this electronic version of Volcanoes of the World.
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